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Question Number 185953 by ajfour last updated on 30/Jan/23

Commented by ajfour last updated on 30/Jan/23

Would it be r≈0.432 ?

Woulditber0.432?

Commented by TUN last updated on 30/Jan/23

S(triangle)=p×r  <=>(1/2)(√(1+r^2 ))×(√((1/x^2 )+1))=(((√(1+r^2 ))+(√((1/r^2 )+1))+r+(1/r))/2)×r  <=>r=0.4320408003

S(triangle)=p×r<=>121+r2×1x2+1=1+r2+1r2+1+r+1r2×r<=>r=0.4320408003

Commented by ajfour last updated on 30/Jan/23

thanks, I understand. wow!

thanks,Iunderstand.wow!

Answered by mr W last updated on 30/Jan/23

Commented by mr W last updated on 30/Jan/23

tan θ=(r/1)=r  cos θ=((r+(r/(tan (θ/2))))/((r/(tan (θ/2)))+(√(1+r^2 ))−r))  cos θ=((1+(1/(tan (θ/2))))/((1/(tan (θ/2)))+(√(1+(1/(tan^2  θ))))−1))  let t=tan (θ/2)  ((1−t^2 )/(1+t^2 ))=((1+t)/(1−t+t(√(1+(((1−t^2 )/(2t)))^2 ))))  t^3 −t^2 +5t−1=0  (s+(1/3))^3 −(s+(1/3))^2 +5(s+(1/3))−1=0  s^3 +((14s)/3)+((16)/(27))=0  s=((((2(√(78)))/9)−(8/(27))))^(1/3) −((((2(√(78)))/9)+(8/(27))))^(1/3)   t=(1/3)(1+((6(√(78))−8))^(1/3) −((6(√(78))+8))^(1/3) )    ≈0.206783  ⇒r=((2t)/(1−t^2 ))≈0.432

tanθ=r1=rcosθ=r+rtanθ2rtanθ2+1+r2rcosθ=1+1tanθ21tanθ2+1+1tan2θ1lett=tanθ21t21+t2=1+t1t+t1+(1t22t)2t3t2+5t1=0(s+13)3(s+13)2+5(s+13)1=0s3+14s3+1627=0s=278982732789+8273t=13(1+67883678+83)0.206783r=2t1t20.432

Commented by ajfour last updated on 30/Jan/23

Thank you Sir. All correct!

ThankyouSir.Allcorrect!

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